Frequencies for first 10,000 rows of rx3v1c1 variable in nhamcsed2006 dataset :

   for rx3, level 1 of multum |
             drug category #1 |      Freq.     Percent        Cum.
------------------------------+-----------------------------------
              anti-infectives |        383        3.83        3.83
        cardiovascular agents |        161        1.61        5.44
central nervous system agents |      1,066       10.66       16.10
        coagulation modifiers |         33        0.33       16.43
      gastrointestinal agents |        143        1.43       17.86
                     hormones |         81        0.81       18.67
         miscellaneous agents |         50        0.50       19.17
         nutritional products |        104        1.04       20.21
           respiratory agents |        280        2.80       23.01
               topical agents |         91        0.91       23.92
        alternative medicines |          1        0.01       23.93
     psychotherapeutic agents |         15        0.15       24.08
         immunological agents |         23        0.23       24.31
             metabolic agents |         25        0.25       24.56
                            . |      7,544       75.44      100.00
------------------------------+-----------------------------------
                        Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016